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How do ACID and database transactions work?
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Atomicity means that you can guarantee that all of a transaction happens, or none of it does; you can do complex operations as one single unit, all or nothing, and a crash, power failure, error, or anything else won't allow you to be in a state in which only some of the related changes have happene...
How do I check if a string is a number (float)?
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Which, not only is ugly and slow
I'd dispute both.
A regex or other string parsing method would be uglier and slower.
I'm not sure that anything much could be faster than the above. It calls the function and returns. Try/Catch doesn't introduce much overhead because the most com...
How to use the 'sweep' function
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sweep() is typically used when you operate a matrix by row or by column, and the other input of the operation is a different value for each row / column. Whether you operate by row or column is defined by MARGIN, as for apply(). The values used for what I called "the other input" is ...
Use space as a delimiter with cut command
...ut of a command aligning some columns with spaces. (and the google search for that lead me here)
In this case a single cut command is not sufficient, and you need to use:
tr -s ' ' | cut -d ' ' -f 2
Or
awk '{print $2}'
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Database cluster and load balancing
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Database clustering is a bit of an ambiguous term, some vendors consider a cluster having two or more servers share the same storage, some others call a cluster a set of replicated servers.
Replication defines the method by which a set of servers remain synchronized without having to...
Mongodb Explain for Aggregation framework
Is there an explain function for the Aggregation framework in MongoDB? I can't see it in the documentation.
3 Answers
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Perform an action in every sub-directory using Bash
I am working on a script that needs to perform an action in every sub-directory of a specific folder.
9 Answers
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How to run JUnit test cases from the command line
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For JUnit 5.x it's:
java -jar junit-platform-console-standalone-<version>.jar <Options>
Find a brief summary at https://stackoverflow.com/a/52373592/1431016 and full details at https://junit.org/junit5/docs/curr...
Vim: Move cursor to its last position
Is it possible in (g)Vim to move the cursor to its previous position (while in normal mode)? Something to cycle back and forth in the list of previous cursor positions would be ideal. But also just to switch to the last location would suffice (something like cd - in bash with directories).
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Exit a Script On Error
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Are you looking for exit?
This is the best bash guide around.
http://tldp.org/LDP/abs/html/
In context:
if jarsigner -verbose -keystore $keyst -keystore $pass $jar_file $kalias
then
echo $jar_file signed sucessfully
else
echo ERROR...